Many people drink coffee to stay alert, but some want to enjoy the flavor of coffee while worrying that caffeine will affect their sleep. How much caffeine does a cup of coffee actually contain? This actually depends on multiple factors such as the coffee bean variety, growing altitude, and extraction method. In this article, Front Street Coffee will systematically sort out the differences in caffeine content among common coffee drinks, from espresso, pour-over, and French press to ice drip and cold brew, providing reference values one by one, while also clarifying two common misunderstandings about caffeine: how to calculate the daily intake limit, and whether roast level really affects caffeine content. For friends who are intolerant to caffeine, the article also provides low-caffeine coffee alternatives.

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"Excuse me, which coffee on the menu has the least caffeine?"

"I really want to drink coffee, but I'm afraid I won't be able to sleep at night if I do~"

In most people's eyes, coffee is a beverage consumed for the purpose of staying alert, but its own aroma also attracts a group of friends who pursue deliciousness, including those who are intolerant to caffeine yet "can't resist the craving," such as the customer mentioned at the beginning by Front Street. In today's article, Front Street will talk about the caffeine content of various coffees, as well as everyone's misunderstandings about caffeine.

What determines the caffeine content of a cup of coffee?

How much caffeine a coffee bean contains first depends on its variety and growing altitude. Taking the two most common coffee varieties as an example, Robusta's caffeine content accounts for about 2–4% of itself, while Arabica is about 0.9–1.4%, usually only half that of Robusta. Most conventional freshly ground coffees on the market use Arabica varieties, and only a few add a small proportion of Robusta to the blend in order to give espresso a richer crema.

The higher the growing altitude, the lower the caffeine content tends to be. High-altitude growing areas have lower temperatures and fewer pests and diseases, so coffee trees do not need to secrete much caffeine to resist pests. This also explains why Robusta grown at low altitudes contains so much caffeine, so this standard mainly applies to Arabica.

Front Street has previously explained that when brewing coffee, lighter flavor molecules are released first, while heavier macromolecular substances dissolve into the water later. Caffeine, with the chemical formula "C8H10N4O2," is a high-mass molecule, so like flavor substances, the amount of caffeine released is also related to extraction time. That is, the longer it brews, the higher the caffeine.

Therefore, the caffeine in espresso-based drinks is not the highest. Drip coffee mainly represented by pour-over and immersion coffee mainly represented by French press have slightly higher caffeine content. Although cold brew and ice drip coffee are extracted at low temperatures, the extremely long extraction time makes their caffeine content higher than the previous types.

The following are Front Street's approximate caffeine content references for common coffee categories based on daily output amounts:

espresso (20g grounds/40g coffee) about 100mg; ( the same for lattes, Americanos, cappuccinos, etc.) pour-over coffee (15g grounds/195ml coffee, 2 minutes) about 90mg; French press (20g grounds/4 minutes) about 135mg; ice drip coffee (one cup with 20g grounds/200ml coffee, 8 hours) about 135mg; cold brew coffee (one cup with 20g grounds/200ml coffee, 12 hours) about 140mg; drip bag coffee (one bag with 10g grounds/120ml coffee) about 50mg; instant coffee (one packet) about 50mg.

Front Street needs to emphasize one more point here: the above values are based on conventional extraction and are not absolute results. The actual caffeine content of a cup of coffee is also related to the extraction yield. For example, if two cups of Front Street Golden Mandheling coffee are brewed here, one with fine grinding and one with coarse grinding, with all other parameters kept the same, then the fine grind will certainly release more flavor substances than the coarse grind, and the caffeine content will naturally be higher as well. In other words, if the coffee grounds are ground finer, the brew will taste richer and also be more stimulating.

Misunderstanding one about caffeine

Online, science articles often tell us that an adult's daily caffeine intake should not exceed 400mg, otherwise it will affect health. Friends who are sensitive to caffeine will then think about how to calculate the specific caffeine value through the drinks they consume, so as to avoid excessive intake. As a result, they ask questions like, "How much caffeine is in a cup of ** coffee?"

You should know that from a barista's perspective, in addition to coffee variety, growing altitude, and brewing time, multiple factors affecting the extraction of coffee substances also determine how much caffeine it contains. Taking pour-over as an example, differences in grind size, water temperature, pouring technique, and coffee-to-water ratio will directly change caffeine extraction, so it is very difficult to measure with a specific value.

Misunderstanding two about caffeine

Front Street has noticed that some friends believe caffeine is related to roast level. They think that the darker the roast, the lighter the coffee beans become, so when weighing the same weight of beans for brewing, dark-roasted coffee requires more beans than light-roasted beans. In addition, the structure of dark-roasted beans is more porous and makes it easier to extract flavor substances, so they believe dark-roasted beans contain more caffeine and have a stronger stimulating effect.

However, many studies show that in fact the roast level of coffee beans has little effect on caffeine. At this point, friends with personal experience may say: I really do feel more energized after drinking dark-roasted coffee! That can only mean that in your subconscious, compared with gentle-tasting acidic coffee, only heavy-bodied bitter coffee can make you feel refreshed and alert. This is also why many people mistakenly believe that espresso has the highest caffeine content.

What should you do if you want to drink coffee but do not want to consume caffeine?

For some friends who are intolerant to caffeine, whether it is instant coffee, bottled coffee, freshly ground espresso, drip pour-over, or long-extracted ice drip and cold brew coffee, the caffeine content of these drinks is still relatively high, and drinking them can easily keep you awake. If friends really want to drink coffee but do not want to consume caffeine, they can choose artificially decaffeinated coffee, as this type of coffee bean contains almost no caffeine.

The above content is compiled by CoffeeHunters, a coffee news website.